Researchers have developed microrobots using algae and magnetic particles that can be guided magnetically to sites in the body and tracked, by spotting the algae’s natural luminescence or using an MRI scanner. The investigators hope that swarms of these tiny robots could help with diagnostics and treatment in areas of the body that are currently difficult to reach.
The research team developed the robots by coating spirulina algae with biocompatible magnetic particles. The robots are approximately the size of a red blood cell and can swim in biological fluids, such as gastric fluid or blood. Using magnetic fields, they can be directed to specific sites in the body. In lab tests, the research team could control the robots and make them accumulate at specific sites in the stomach of rats.
As the algae are naturally luminescent, they can be tracked in more superficial tissues using in vivo fluorescence imaging, whereas MRI allows the scientists to visualize the robots in deeper tissues. As such, the microrobots might allow for targeted drug delivery in difficult to access areas of the body. The team showed that the microrobots can release anticancer compounds as the algal core degrades, providing selective anti-cancer cytotoxicity.
Another clinical possibility lies in diagnostics, as the robots might also be able to sense chemical signals related to disease, and so could act as probes for remote diagnoses. However, more work is needed to assess if the system is suitable for these applications.
“A small-scale robot that can be remotely guided, is easily tracked and harmlessly biodegrades, potentially overcomes many of the challenges faced by minimally invasive therapies,” said Qi Zhou, a researcher at the University of Edinburgh who was involved at the study. “We hope our discoveries will pave the way for the development of useful diagnostics or treatments.”
Study in Science Robotics: Multifunctional biohybrid magnetite microrobots for imaging-guided therapy…